U.S. patent application number 15/892345 was filed with the patent office on 2018-06-14 for moveably-coupled screen actuators.
This patent application is currently assigned to Dolby Laboratories Licensing Corporation. The applicant listed for this patent is Dolby Laboratories Licensing Corporation. Invention is credited to Wilson ALLEN, Brad BASLER, Trevor DAVIES, Douglas J. GORNY.
Application Number | 20180164602 15/892345 |
Document ID | / |
Family ID | 53494062 |
Filed Date | 2018-06-14 |
United States Patent
Application |
20180164602 |
Kind Code |
A1 |
BASLER; Brad ; et
al. |
June 14, 2018 |
Moveably-Coupled Screen Actuators
Abstract
A speckle damping system for dampening speckle on a projection
screen for a projection display system employing coherent or
partially coherent light sources (e.g., lasers, LEDs) are
disclosed. In one embodiment, a rotatably coupled system is
disclosed, comprising: a set of actuators; a set of rotatably
coupled mounts, each of said set of rotatably coupled mount capable
of mounting at least one said actuator; and wherein said at least
one actuator mounted on said rotatably coupled mount is in moveable
mechanical communication with said projection screen. In another
embodiment, a linearly coupled system is disclosed comprising: a
set of actuators; a set of linearly coupled mounts, each of said
set of linearly coupled mount capable of mounting at least one said
actuator; and wherein said at least one actuator mounted on said
linearly coupled mount is in moveable mechanical communication with
said projection screen.
Inventors: |
BASLER; Brad; (San Mateo,
CA) ; DAVIES; Trevor; (Walnut Creek, CA) ;
GORNY; Douglas J.; (Pacifica, CA) ; ALLEN;
Wilson; (Mill Valley, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dolby Laboratories Licensing Corporation |
San Francisco |
CA |
US |
|
|
Assignee: |
Dolby Laboratories Licensing
Corporation
San Francisco
CA
|
Family ID: |
53494062 |
Appl. No.: |
15/892345 |
Filed: |
February 8, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15109791 |
Jul 5, 2016 |
9921416 |
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PCT/US2015/010064 |
Jan 2, 2015 |
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15892345 |
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61923256 |
Jan 3, 2014 |
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61982530 |
Apr 22, 2014 |
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62096343 |
Dec 23, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 27/48 20130101;
G03B 21/562 20130101 |
International
Class: |
G02B 27/48 20060101
G02B027/48; G03B 21/56 20060101 G03B021/56 |
Claims
1. A speckle dampening system for dampening speckle on a projection
screen for a projection display system, said projection display
system comprising coherent light sources, said system comprising: a
set of actuators, each said actuator capable of emitting a
vibration of a set of desired frequencies; a set of rotatably
coupled mounts, each of said set of rotatably coupled mount capable
of mounting at least one said actuator; and wherein said at least
one actuator mounted on said rotatably coupled mount is in moveable
mechanical communication with said projection screen.
2. The system of claim 1 wherein said projection system further
comprises one of a group, said group comprising: lasers, LEDs,
coherent light sources and partially coherent light sources.
3. The system of claim 1 wherein said actuators comprise one of a
group, said group comprising: mechanical actuators, voice coils,
ultrasound actuators, electromagnet and solenoid.
4. The system of claim 1 wherein said rotatably coupled mount
further comprises: a first support portion, said first support
portion capable of mounting an actuator; a second support portion,
said second support portion capable of maintaining a substantially
stable frame for said first support portion; and a pivot, said
pivot mechanically mating said first support portion to said second
support portion.
5. The system of claim 4 wherein said first support portion
comprise a first length that is substantially longer than the range
of motion of the screen.
6. The system of claim 5 wherein said first length substantially
reduces the angular variation of said actuator with respect to the
plane of said projector screen.
7. The system of claim 5 wherein said first length substantially
allows significant Z-axis movement without significant change of
angle of the first support portion with respect to the plane of
said projector screen.
8. The system of claim 5 wherein said first length substantially
comprises a natural frequency that is substantially different from
the frequency of the vibration of said actuator.
9. The system of claim 4 wherein said second support portion
comprises a substantially fixed frame.
10. The system of claim 4 wherein said second support portion
comprises a substantially adjustable frame.
11. The system of claim 4 wherein said system further comprises an
additional mass, said additional mass placed on said system capable
of adjusting the force of said actuator upon said projection
screen.
12. The system of claim 1 wherein said system further comprises a
magnetic coupling system, said magnetic coupling system capable of
maintaining a desired mechanically communication of said actuator
with said projection screen.
13. The system of claim 12 wherein said magnetic coupling system
further comprises: a first magnetic element, said first magnetic
element affixed to said projector screen; a second magnetic
element, said second magnetic element affixed to substantially
proximal to said actuator; and said second magnetic element being
substantially proximal to said first magnetic element such that the
magnetic force between said first and said second magnetic elements
capable of substantially maintaining a desired mechanical
communication of said actuator with said projection screen.
14. The system of claim 13 wherein said magnetic coupling system
further comprises: a controller; at least one of said first
magnetic element and said second magnetic element comprises a
variable electromagnet; and said variable electromagnet capable of
varying its magnetic field under control of said controller.
15. The system of claim 14 wherein said magnetic coupling system
further comprises: a sensor, said sensor capable of detecting a
characteristic of the mechanical communication of said actuator
with said projection screen; and wherein said sensor capable of
sending sensed data of said characteristic to said controller and
further wherein said controller sends control signals to said
electromagnet in response to said sensed data.
16. A speckle dampening system for dampening speckle on a
projection screen for a projection display system, said projection
display system comprising coherent light sources, said system
comprising: a set of actuators, each said actuator capable of
emitting a vibration of a set of desired frequencies; a set of
linearly coupled mounts, each of said set of linearly coupled mount
capable of mounting at least one said actuator; and wherein said at
least one actuator mounted on said linearly coupled mount is in
moveable mechanical communication with said projection screen.
17. The system of claim 16 wherein said projection system further
comprises one of a group, said group comprising: lasers, LEDs,
coherent light sources and partially coherent light sources.
18. The system of claim 16 wherein said actuators comprise one of a
group, said group comprising: mechanical actuators, voice coils,
ultrasound actuators, electromagnet and solenoid.
19. The system of claim 16 wherein said linearly coupled mount
further comprises a housing; said housing capable of mounting said
actuator; a set of bearing, said set of bearing movably supporting
said housing; and a bias, said bias applied to aid housing and
capable of maintaining a desired mechanical communication of the
actuator to said projector screen.
20. The system of claim 19 wherein said bias further comprises a
mass and a pulley wherein said mass communicates a force to said
housing to maintain a desired mechanical communication of the
actuator to said projector screen.
21. The system of claim 16 wherein said system further comprises a
magnetic coupling system, said magnetic coupling system capable of
maintaining a desired mechanically communication of said actuator
with said projection screen.
22. The system of claim 21 wherein said magnetic coupling system
further comprises: a first magnetic element, said first magnetic
element affixed to said projector screen; a second magnetic
element, said second magnetic element affixed to substantially
proximal to said actuator; and said second magnetic element being
substantially proximal to said first magnetic element such that the
magnetic force between said first and said second magnetic elements
capable of substantially maintaining a desired mechanical
communication of said actuator with said projection screen.
23. The system of claim 22 wherein said magnetic coupling system
further comprises: a controller; at least one of said first
magnetic element and said second magnetic element comprises a
variable electromagnet; and said variable electromagnet capable of
varying its magnetic field under control of said controller.
24. The system of claim 23 wherein said magnetic coupling system
further comprises: a sensor, said sensor capable of detecting a
characteristic of the mechanical communication of said actuator
with said projection screen; and wherein said sensor capable of
sending sensed data of said characteristic to said controller and
further wherein said controller sends control signals to said
electromagnet in response to said sensed data.
25. The system of claim 19 wherein said bias further comprises: a
spring, said spring attached to said actuator; and further wherein
the force from said spring substantially maintains a desired
mechanical communication between said actuator and said projector
screen.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/109,791 filed on Jul. 5, 2016, which claims
benefit to International Patent Application No. PCT/US2015/010064
filed on Jan. 2, 2015, which claims the benefit of priority to U.S.
Provisional Patent Application No. 61/923,256 filed on Jan. 3,
2014; U.S. Provisional Patent Application No. 61/982,530 filed on
Apr. 22, 2014; and U.S. Provisional Patent Application No.
62/096,343 filed on Dec. 23, 2014, all entireties of which are
incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to projector displays systems
and, more particularly, to systems and methods of reducing and/or
dampening speckle on a projection screen.
BACKGROUND OF THE INVENTION
[0003] In projector systems that use either coherent light or
partially coherent light sources (e.g., lasers, LEDs or the like),
an issue of speckle may occur. Speckle arises due to the
interference of the coherent or partially coherent light that
reflects and/or scatters from a projector screen. Speckle is
typically an undesirable visible artifact that projector system
designers seek to eliminate and/or abate.
[0004] It is known in the art that inducing vibrations on the
projector screen (e.g., in particular, in the direction of the
viewers, or z-axis (where x-, y-axis substantially describe the
plane of the screen) tend to reduce and/or eliminate such
speckle.
[0005] Several solutions are noted in the art--for example: [0006]
(1) United States Patent Application 20120206784 to CHAN et al.,
published on Aug. 16, 2012 and entitled "DEVICE FOR REDUCING
SPECKLE EFFECT IN A DISPLAY SYSTEM"; [0007] (2) United States
Patent Application 20110194082 to Desai, published on Aug. 11, 2011
and entitled "MICROELECTROMECHANICAL SYSTEM WITH REDUCED SPECKLE
CONTRAST"; [0008] (3) United States Patent Application 20090034037
to Khan et al., published on Feb. 5, 2009 and entitled "METHOD AND
SYSTEM FOR REDUCING SPECKLE BY VIBRATING A LINE GENERATING
ELEMENT"; [0009] (4) United States Patent Application 20130010356
to Curtis et al., published on Jan. 10, 2013 and entitled "SPECKLE
REDUCTION USING SCREEN VIBRATION TECHNIQUES AND APPARATUS"; [0010]
(5) United States Patent Application 20060238743 to Lizotte et al.,
published on Oct. 26, 2006 and entitled "SPECKLE REDUCTION OPTICAL
MOUNT DEVICE"
[0011] all of which are hereby incorporated by reference in their
entirety.
SUMMARY OF THE INVENTION
[0012] A speckle damping system for dampening speckle on a
projection screen for a projection display system employing
coherent or partially coherent light sources (e.g., lasers, LEDs)
are disclosed. In one embodiment, a rotatably coupled system is
disclosed, comprising: a set of actuators; a set of rotatably
coupled mounts, each of said set of rotatably coupled mount capable
of mounting at least one said actuator; and wherein said at least
one actuator mounted on said rotatably coupled mount is in moveable
mechanical communication with said projection screen. In another
embodiment, a linearly coupled system is disclosed comprising: a
set of actuators; a set of linearly coupled mounts, each of said
set of linearly coupled mount capable of mounting at least one said
actuator; and wherein said at least one actuator mounted on said
linearly coupled mount is in moveable mechanical communication with
said projection screen.
[0013] In another embodiment, both rotatably coupled systems and
linearly coupled systems may further comprise a magnetic coupling
system, comprising: a first magnetic element, said first magnetic
element affixed to said projector screen; a second magnetic
element, said second magnetic element affixed to substantially
proximal to said actuator; and said second magnetic element being
substantially proximal to said first magnetic element such that the
magnetic force between said first and said second magnetic elements
capable of substantially maintaining a desired mechanical
communication of said actuator with said projection screen.
[0014] Other features and advantages of the present system are
presented below in the Detailed Description when read in connection
with the drawings presented within this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Exemplary embodiments are illustrated in referenced figures
of the drawings. It is intended that the embodiments and figures
disclosed herein are to be considered illustrative rather than
restrictive.
[0016] FIG. 1A is front view of a conventional projector screen
with mechanical actuators coupled to the screen on the back of the
screen.
[0017] FIG. 1B is a side view of a conventional projector screen
with mechanical actuators coupled to the screen in a substantially
fixed manner.
[0018] FIGS. 2A and 2B depict a mechanical actuator that is
rotatably coupled to a support structure that tends to provide
proper coupling between the actuator and the screen--that have a
substantially flat engaging surface and a substantially curved
engaging surface, respectively.
[0019] FIGS. 3A and 3B depict two alternative embodiments of a
rotatably coupled actuator system.
[0020] FIGS. 3C and 3D depict two additional alternative
embodiments of a rotatably coupled actuator system--as shown in
FIGS. 3A and 3B and additionally comprising a counterbalance
weight.
[0021] FIG. 3E depicts one additional alternative embodiment of a
rotatably coupled actuator system comprising a dynamically varying
weight as biased against the screen.
[0022] FIGS. 4A and 4B depict two alternative embodiments of a
linear coupled actuator system.
[0023] FIG. 5 depicts one embodiment of a magnetically coupled
actuator system.
[0024] FIG. 6 depicts one embodiment of a servo-motor coupled
actuator system.
[0025] FIGS. 7A through 7H are a set of various perspective
drawings of one pendulum embodiment.
[0026] FIGS. 8A through 8H are a set of various perspective
drawings of another pendulum embodiment.
[0027] FIG. 9A shows an analysis of several embodiments of pendulum
screen shakers described herein.
[0028] FIG. 9B depicts one such embodiment of a pendulum screen
shaker comprising such a counterweight.
[0029] FIGS. 10A through 10B depict several different views of one
particular embodiment of a pendulum screen shaker comprising a
counterweight.
[0030] FIGS. 11A through 11C depict several other different views
of one particular embodiment of a pendulum screen shaker comprising
a counterweight.
[0031] FIGS. 12A and 12B depict one embodiment of a pendulum screen
shaker comprising a counterweight at rest and with relative motion
between positions.
[0032] FIG. 13 depicts an embodiment of a dual-linkage pendulum
screen shaker.
[0033] FIG. 14 depicts an embodiment of a diving board voicecoil
mount on a screen shaker.
DETAILED DESCRIPTION
[0034] Throughout the following description, specific details are
set forth in order to provide a more thorough understanding to
persons skilled in the art. However, well known elements may not
have been shown or described in detail to avoid unnecessarily
obscuring the disclosure. Accordingly, the description and drawings
are to be regarded in an illustrative, rather than a restrictive,
sense.
[0035] As utilized herein, terms "component," "system,"
"interface," "controller" and the like are intended to refer to a
computer-related entity, either hardware, software (e.g., in
execution), and/or firmware. For example, any of these terms can be
a process running on a processor, a processor, an object, an
executable, a program, and/or a computer. By way of illustration,
both an application running on a server and the server can be a
component and/or controller. One or more components/controllers can
reside within a process and a component/controller can be localized
on one computer and/or distributed between two or more
computers.
[0036] The claimed subject matter is described with reference to
the drawings, wherein like reference numerals are used to refer to
like elements throughout. In the following description, for
purposes of explanation, numerous specific details are set forth in
order to provide a thorough understanding of the subject
innovation. It may be evident, however, that the claimed subject
matter may be practiced without these specific details. In other
instances, well-known structures and devices are shown in block
diagram form in order to facilitate describing the subject
innovation.
Introduction
[0037] The current state of the art for speckle reduction of
laser-based projected images is to vibrate the projection screen
very slightly in the direction of the projected light, along the
line of sight of a viewer. The most effective implementation of
this technique is to install an array of mechanical
shakers/actuators (e.g., "Voice Coils", ultrasound transducers,
solenoid, shaker and the like) mounted behind the projection
screen.
[0038] Such references employing such voice coils are disclosed in:
[0039] (1) United States Patent Application 20120019918 to Dunphy
et al., published on Jan. 26, 2012 and entitled "SYSTEM AND METHOD
FOR REDUCING VISIBLE SPECKLE IN A PROJECTION VISUAL DISPLAY
SYSTEM"; and [0040] (2) United States Patent Application
20100312106 to Blalock et al., published Dec. 9, 2010 and entitled
"ULTRASOUND IMAGING BEAM-FORMER APPARATUS AND METHOD"
[0041] and herein incorporated by reference in its entirety.
[0042] One possible drawback to using mechanical actuators/shakers
(of any type or kind--such as voice coils, ultrasound actuators or
the like) is that it may be desired to have accurate placement of
the actuator very closely to the back of the screen, but not so
closely that the actuator pushes against the screen. In such a
case, the outline of the actuator may produce a "dimple" or an
otherwise impression of itself, which may be easily visible and
distracting.
[0043] FIG. 1A shows a front view of a projector screen 102 with an
array of conventional mechanical actuators 104 in physical
proximity with the projector screen from behind the screen. FIG. 1B
is a cross-sectional view of the conventional array of actuators
104 in contact with screen 102. Actuators 104 may be held in
position by support 106--e.g., typically in a fixed position. A
projector system is depicted in schematic format in FIG. 1B.
Projector system 100 may comprise a light source 108 (typically,
coherent or partially coherent sources, like lasers or LEDs), a
modulator 110 which may receive light from source 108 and create a
modulated light source to illuminate projector optics 112 to form a
final image on screen 102.
[0044] Although the laser and/or partially coherent projector
system may be of any type or construction known, in some
embodiments, the laser projection system may comprise, for example,
a dual modulation DMD projection system. The dual modulation system
may comprise a reduced initial amount of speckle operation of the
screen shakers compared to commercial single modulation (e.g., 3
chip DLP) laser projectors, and which the reduced initial amount of
speckle is further reduced by operation of the screen shakers.
[0045] The laser projection system may comprise a 3 chip DLP
projection system. The laser projection system comprises a 3 chip
DLP six-primary laser projection system. The laser projection
system comprises a 6 chip DLP six primary projection system. The
laser projection system produces images on the screen having a
contrast ratio in excess of 99,999:1.
[0046] The laser projection system produces images on the screen
having a dynamic contrast ratio between scenes in excess of
999,999:1. The laser projection system produces images on the
screen having a single frame contrast ratio of at least 100,000:1
and a dynamic intra frame contrast ratio in excess of
1,000,000:1.
[0047] As noted, if the contact between the actuators 104 and
screen 102 is not substantially precise, then an outline of the
actuators 104 may become visible upon the screen and adversely
affect the speckle reduction as desired. In fact, if the screen 102
is induced to move at all (e.g., by change in air pressure due to
air conditioning or, possibly from a door to the theater opening
and/or closing, or from the expansion and/or contraction of the
screen with temperature), then the actuators 104 may also become
visible or they may lose contact with the screen resulting in the
speckle reduction being abated. It may be desirable that the force
of the actuator against the screen is maintained substantially
constantly over the range of movement of the screen.
[0048] In many embodiments, it may be desirable to induce
vibrations (e.g., from actuators) that are more than pure Z-axis
vibration (i.e., vibrations along the viewer's line of sight to the
screen). Pure Z-axis may not be sufficient in many case to mitigate
speckle. In many cases, the interference patterns may be quite deep
(e.g. if the viewer perceives speckle and moves his/her head closer
and farther from the screen without moving side to side or up and
down, the speckle pattern may tend to change very slowly).
Similarly, moving the screen in the Z axis may not change the
interference pattern significantly. Thus, vibrating the screen in
the Z axis (e.g., where the intention is for the eye to integrate
over the variations in interference patterns) may not be effective.
Instead, speckle may be better reduced by creating waves on the
screen.
[0049] So, in the case of using stationary actuators (e.g., as in
FIGS. 1A and 1B), if the actuators are too close to the screen, the
viewers may perceive two problems: (i) dimples (made by the contact
of the actuator on the screen) and (ii) speckle in the dimples only
(because in these areas there tend to be only Z-axis movement). For
the case where the actuators are too far from the screen, they
don't even touch the screen, there is no vibration and there is no
speckle reduction at all.
One Embodiment
[0050] FIG. 2A depicts one embodiment of an actuator support
structure 200. Structure 200 may be a rotatably coupled mount,
where the mount is capable of mounting or attaching an actuator 104
on a first support portion 202. Any suitable means of mounting
and/or attaching the actuator to the first support portion may be
suitable--e.g., mechanical clipping, affixing, gluing, soldering or
the like. First support beam 202 may be, in turn, rotatably
attached to a second support portion 206--e.g., possibly by a pivot
204. Second support portion 206 may be fixedly or adjustably set,
affixed and/or supported in place to any other suitable structure
and/or position in the theater (not shown)--e.g., in order to
provide a substantially suitable stable frame for the first support
portion. It will be appreciated that, although only one actuator is
shown on a support structure, it is possible to construct a set
and/or an array of such support structure(s) that support the
entire set of actuators for a screen--either individually, a subset
or the entire set of actuators. The present application is not
limited to merely one support structure for one actuator; but the
scope of the present application encompasses all such support
structures.
[0051] In one embodiment, second support portion 206 may be
(optionally) adjustably set--e.g., for example, as shown by dotted
line 201. This adjustable setting may be preferentially set by
theater personnel--e.g., to adjust the pressure actuator 104 makes
upon screen 102 and/or to adjust the position of the actuator in
the middle range. In one embodiment, an adjustment weight, as
described herein, may be set to adjust the pressure suitably so
that the actuator 104 makes desirable contact with the screen (e.g.
to abate and/or dampen speckle); but not so much as to make a
visibly noticeable dimple in the screen to the viewers (and,
possibly, abate and/or dampen speckle reduction).
[0052] Once a pivot point 204 is set, first support portion 202 may
be rotatable about the pivot--e.g., for example as shown by arc
203. Rotatable movement of the actuator 104 may be desirable in
certain situations. For example, if the screen has some motion
(e.g., as might be induced by changes in air pressure, ground
movements or the like), then the actuator may be allowed to move in
response to the screen and continue to in contact with the screen
and thus, provide continued speckle reduction. In addition, movable
actuator may be able to dampen the motion of the screen itself.
[0053] In FIG. 2A, it may be seen that actuator 104 may have a
substantially flat surface for engaging with the screen. However,
in FIG. 2B, actuator 104b may have some form of curved feature
and/or surface in which to engage with the screen. Such a curved
surface may be desirable if the displacements of the actuator with
respect to the screen cause a sharp edge of the actuator to become
visible to the viewer and/or have an undesirable effect on the
dampening of the speckle. It may be understood that the curvature
of the actuator may be circular or spherical (or a portion
thereof), bent, bowed, arched and/or arcuate--in such a manner as
to provide no (or at least less) detectable edges of the actuator
when there is relative movement of the screen with the
actuator.
[0054] Such a curved actuator may be desirable in operation, if the
actuator is not substantially parallel to the screen (e.g. due to
misalignment of the mount or large screen displacements). In such a
case, one edge of the flat actuator may press harder against the
screen surface which in extreme cases may cause an arc-shaped
imprint on the screen. Thus, a curved actuator (for example, one
where the actuator surface may be a section of a larger sphere)
would tend to present a consistent contact surface over a range or
rotations. The curvature radius may be between a few inches to `d`
the length of the pendulum. In addition, as noted above, pure
Z-axis vibration may not reduce speckle--and in particular if
speckle is still apparent within the contact area of a flat
actuator. The curved actuator would tend to reduce the area that
moves simply in the Z axis and improve the speckle reduction in the
contact area.
[0055] In many embodiments, it may be desirable to suitably
construct the length of the first support/pendulum portion for
several advantages, such as: [0056] (1) If the pendulum length is
long with respect to the range of motion of the screen (e.g., that
the actuator had to follow) then the variation in angle is small
and that reduces any asymmetrical imprint of the skewed actuator on
the screen. If the actuator is small then, for any angle, the
effect of the asymmetrical imprint of the actuator is reduced. A
larger ratio of pendulum length to actuator size reduces the
imprint but not the angle. Angular variations may tend to cause an
edge of the actuator to become visible. [0057] (2) For the pendulum
support schemes, the moment of force varies with large angles of
the pendulum and hence the force applied through the actuator to
the screen varies with angle. If the pendulum is long, then it may
allow for significant Z-axis movement without significant change of
angle of the pendulum and hence may tend to maintain an
approximately constant force on the screen. [0058] (3) The pendulum
schemes may have a natural frequency (e.g., if the screen was to be
removed and the actuator pushed, it would tend to oscillate at its
natural frequency). It may be desirable that the natural frequency
be designed to be different from the frequency of the actuator
vibration otherwise the pendulum may vibrate instead of the screen.
A long pendulum may tend to allow for a low natural frequency.
Other Embodiments
[0059] FIGS. 3A and 3B depict alternative embodiments of an
actuator support structure. As may be seen, an additional mass may
be placed advantageously on the support structure. In these
embodiments, it may be possible to adjust the force with the
additional mass (e.g., as placed on either the first support
portion or the second support portion) on the screen as desired for
the screen material. In both FIGS. 3A and 3B, the force may be
adjusted by adjusting the mass shown.
[0060] For example, the mass may be adjusted as follows: [0061] (1)
In FIG. 3A--Let distance 310 (I.sub.1) denote the distance from the
pivot to the attachment point of the mass, and distance 312
(I.sub.2) denote the distance from the pivot to the center of mass
of the actuator and let P.sub.1 be the length of the pendulum. The
force on the screen would be:
[0061] F = m * g * ( l 1 P 1 ) - m cg * g * ( l 2 P 1 )
##EQU00001## where g is the acceleration due to gravity and m is
the mass of the attached mass and m.sub.cg is the mass of the
actuator at the center of gravity of the actuator. [0062] (2) In
FIG. 3B--The force on the screen would be:
[0062] F=m*g
[0063] FIGS. 3C and 3D are additional embodiments of actuator
support structures (substantially following the embodiments of
FIGS. 3A and 3B) in which the support structure is extended past
pivot points 204a and a counterweight 320 is supplied to
advantageously provide desirable balance of the actuator support
structure.
[0064] FIG. 3E is yet another embodiment of an actuator support
structure in which a dynamically variable and/or varying mass
and/or force 313 is applied to dynamically vary the bias of the
actuator against the screen. Variable mass and/or force 313 may be
supplied by a variable spring force, variable weights, piezo
structures and/or any other suitable mass and/or force known. Such
variable weight and/or force may in addition be applied according
to signals supplied by a controller 314. Such controller may
receive input signals from one or more possible sensors--e.g., a
photo sensor 316a and/or a force sensor 316b. Photo sensor 316a may
be a camera and/or some image capture/detection device that is
sensing/regarding the image on the screen and detecting the amount
of (or any change in) the speckle displayed on the screen. If the
photo sensor sends signals that the controller may interpret that a
change (e.g., either more or less) in bias of the actuator against
the screen may improve the speckle reduction, then the controller
may send signals to the variable weight/force 313 to apply the
desired change in bias.
[0065] In the case of the force detector 316b, these detectors may
be piezo force sensors, embedded in or associated with the actuator
(or any other known means of detecting contact force and/or bias
that is in mechanical communication with the screen) that send
signals to the controller 314 in order to change bias of the
variable weight and/or force as desired.
[0066] In another embodiment, a method for correcting for artifacts
and/or adjusting image projection includes the steps of
illuminating a screen with a test image, identifying at least one
shaker induced artifact, and adjusting at least one shaker
parameter to reduce at least one shaker induced artifact. The at
least one parameter comprises, for example, one of a frequency of
the shaker, a shape of the shaker, a motion induced by the shaker,
a pressure of the shaker (e.g., pressure against or placement of
the shaker adjacent to the screen), a pendulum balance of the
shaker, a contact area of the shaker, a modulation of the shaker,
an angle of the shaker, a mechanical adjustment of an assembly
holding the shaker, an adjustment changing a proximate position of
the shaker relative to the screen. The at least one shaker induced
artifact may comprise, for example, a speckle pattern associated
with a contact area (or "contact" area) of the shaker. The step of
adjusting may comprise, for example, activating a remote control.
The adjusting may comprise manual placement of weights on a lever
that, upon movement, brings a shaker back into equilibrium adjacent
and in "contact" with the screen (contact without significant
pressure).
[0067] The step of activating the remote control may comprise
identifying at least one of a plurality of shakers and sending a
control signal to the identified shaker(s). The step of adjusting
may comprise, activating a remote control for a group or plurality
of shakers adjacent to the screen. The identified shakers comprise
a set of shakers within a plurality of shakers, and the control
signal is configured to adjust each of the identified shakers in a
similar way.
[0068] The step of adjusting may comprise, for example, adjusting a
moment of inertia of mechanical device configured to place the
shaker at a location directly adjacent to a non-viewing side of the
screen. The mechanical device may comprise, for example, a weighted
swing-arm. The step of adjusting may comprise moving the weight
with respect to the swing-arm. The mechanical device may comprise a
movable extension attached to the weight and wherein the adjustment
comprises increasing or decreasing an amount of leverage the weight
applies through the extension to an arm of the mechanical device by
extending or retracting the movable extension. Extending or
retracting the movable extension, or other types adjustment
discussed elsewhere herein, may be electrically activated, and may
be activated by remote control. Adjusting the moment of inertia may
comprise adding weight to the swing arm or other components as
described elsewhere herein to which the shaker is attached.
[0069] The step of adjusting may comprise, for example, adjusting
the shaker such that a screen coupler attached to the shaker is
directly adjacent and parallel to the screen. The adjusted shaker
may be, in various embodiments, for example, in contact with the
screen but balanced such that it does not exert pressure on the
screen. The adjusted shaker is, for example, as close as possible
to the screen for maximum speckle reduction with a minimum of test
image artifacts induced by the shaker and coupler.
[0070] The adjusted shaker may be, for example, in contact with the
screen and balanced such that it exerts enough pressure on the
screen to maintain contact with the screen, but not enough pressure
to induce pressure/contact related artifacts in images displayed on
the screen.
[0071] The adjusted shaker coupler may be, for example, in contact
with the screen and balanced such that it exerts enough pressure on
the screen to remain in contact and adjacent to the screen without
causing a protrusion of the screen.
[0072] The method may place the shaker such that the contact and
adjacency of the shaker coupler remains (moves back to equilibrium)
in light of screen movement due to any one or combination of air
conditioning or ventilating systems, air currents to entrance
and/or exit door openings, or other movements normally associated
with a viewing screen during use, including motion induced by theme
park ride cars, explosions, heat induced motion, fans, or motion of
props when said screen is installed at a theme park ride.
[0073] The shaker comprises, for example, a base shaking device, a
coupler attached to the base shaking device, and a placement device
attached to the base shaking device, the method further comprising
the step of maintaining a face of the coupler parallel and adjacent
to the screen.
[0074] In another embodiment, a reduced speckle laser projection
system may comprise, for example, a screen installed at a venue, a
laser projection system configured to project images onto the
screen, and a plurality of screen shakers disposed on a non-viewing
side of the screen. Each screen shaker may be, for example, movably
held in position via a corresponding placement device configured to
place the screen shaker directly adjacent to the screen with an
amount of pressure that does not substantially change when the
screen moves. The amount of pressure is, for example, mostly
negligible, which is, for example, an amount of pressure does not
cause any viewable surface variation on a viewing side of the
screen. The surface variations on a viewing side of the screen from
one or more of mechanical, acoustical, or vibrational forces of the
shaker. The shaker is configured to cause surface variations
comprising motion in a plane of the screen caused by the shaker.
The surface variations on a viewing side of the screen are, for
example, caused by one or more of mechanical, acoustical, or
vibrational forces of the shaker and not by a pressure of the
shaker on the screen.
[0075] The placement device may comprise, for example, a dual arm
dual-pivot swing (as discussed in various embodiments further
herein) that maintains a coupler of the shaking device parallel to
the screen. In one embodiment, the placement device comprises a
dual arm dual-pivot swing that maintains a coupler of the shaking
device parallel to the screen while moving due to screen movement.
The placement device may comprise, for example, parallelism
mechanism configured to maintain a coupler of the shaker parallel
to the screen while moving due to screen movement. The placement
device may comprise a coupler motion parallel placement mechanism
configured to maintain a coupler of the shaker parallel where it
would otherwise not be parallel due to shaker induced movement.
[0076] The placement device may comprise, for example, a coupler
motion parallel placement mechanism configured to maintain a
coupler of the shaker parallel where it would otherwise not be
parallel due to shaker induced movement.
Another Embodiment
[0077] FIG. 4A is yet another embodiment of an actuator support
structure 300. In this embodiment, instead of being rotatably
coupled, the actuators may be linearly coupled (or otherwise in
desired mechanical communication) to the screen by a set of linear
bearings 404 that may be mounted in a housing movably resting on
the bearings. In FIG. 4, the actuator may be attached to a housing
406--and some bias structure or means may be applied to maintain a
desired mechanical communication of the actuator to the screen. One
bias may comprises a pulley 410 and a mass 402. In this embodiment,
the force on the screen is proportional to the mass. In this
embodiment, it may be noted that the force is substantially
constant over the full range of motion of the linear bearing, as
follows:
F=m*g
[0078] FIG. 4B is another linearly coupled actuator to the screen.
In this embodiment, instead of a weight and pulley, the actuator
may be biased to the screen by a spring 420 that has a suitable
biasing force to maintain appropriate contact with the screen. In
one embodiment, it may be possible to adjust the tension on the
spring such that the proper mechanical communication between the
actuator and the screen is substantially zero force and that any
deviation from that zero provides a counter-balancing force to
restore that zero. In another embodiment, a spring may be placed
such that, for the necessary range of motion, its force may tend to
be maintained within an acceptable upper and lower bound. Such a
spring may be not unlike a pendulum that only "swings" at the
bottom of its arc. As such, this spring would only operate in a
range where the force (while not constant) is substantially
unchanged. In one embodiment, the actuator may be affixed to the
screen in any manner known, including adhesive, glue, tape, Velcro,
magnetic stripes or the like.
Magnetic Field Coupling and/or Modulation
[0079] In some embodiments, it may be desirable to employ systems,
methods and/or techniques in order to maintain the proper coupling
and/or bias of the actuator to the screen. In one embodiment, it
may be possible to employ magnetic field coupling (e.g., whether
static or varying) in order to maintain the proper coupling.
[0080] FIG. 5 is one embodiment of such a magnetic coupling system
as made in accordance with the principles of the present
application. Actuator 104 may further comprise an actuator magnetic
element 504. Actuator magnetic element 504 may be either a
permanent magnet or a varying electromagnetic element. If magnetic
element 504 is a varying electromagnet (e.g., a solenoid or the
like), then there may be an optional controller 506 in order to
vary the magnetic field desirably. In addition, 506 may comprise
optional sensors that may detect any number of parameter that may
be useful in the governing of the coupling and/or bias of the
actuator to the screen. Suitable sensors might include (but are not
limited to): position sensors, motion sensors, accelerometers or
the like.
[0081] On the screen 102, there may be place a screen magnetic
element 502--which may be either permanent (e.g. magnetic bar,
magnetic strip or the like) or varying electromagnet (e.g., with
any suitable controller and/or sensors, not shown).
[0082] In one case, the system may be designed or built to detect
the amount of force, or relative positions, of the actuator to the
screen. If the system employs some varying magnetic field, then the
system may be designed with the sensors providing proper feedback
on position, force, velocity, and/or acceleration in order to
maintain desired coupling.
[0083] It will be appreciated that the dashed lines in FIG. 5
denote that the magnetic coupling schemes as mentioned above may be
employed in either the rotatably coupled systems and/or the
linearly coupled systems.
Other Embodiments
[0084] FIG. 6 is yet another embodiment of an actuator coupled to
screen system that further comprises at least one servo-motor (e.g.
604, if actuator is rotatably coupled; 606, if actuator is linearly
coupled). In addition, there may be at least one sensor 608 that
may detect some characteristic (e.g., the position, speed and/or
acceleration of the actuator in relation to the screen) of the
mechanical communication of the actuator in relation to the screen.
Signals from these optional sensor(s) may be input into controller
610 that may, in turn, control servo-motors (e.g., 604 or 606) to
provide the desired bias to the actuators in relation to the
screen.
Particular Pendulum Embodiments
[0085] FIGS. 7A through 7H are a set of various perspective
drawings of one pendulum embodiment (700). As may be seen, actuator
104 is mounted and/or affixed to first support member 702--which is
rotatably mounted to second support member 706 via a pivot 704.
[0086] FIGS. 8A through 8H are a set of various perspective
drawings of another pendulum embodiment (800). As may be seen,
actuator 104 is mounted and/or affixed to first support member
802--which is rotatably mounted to second support member 806 via a
pivot 804. An additional mass 810 is mounted on the first support
member 802, as shown.
Embodiments with Counterweight
[0087] FIG. 9A shows an analysis of several embodiments of pendulum
screen shakers given above. As may be seen, pendulum screen shaker
902 of length `l` is pivoted about point `P` applying a force `F`
against the screen at point `S`. m.sub.s represents the mass of the
voicecoil and washers at bottom of pendulum. m.sub.w represents a
mass hung from an arm of length `r` attached to the screen shaker
at the pivot, perpendicular to the pendulum.
[0088] This analysis looks for the variation in force `F` vs the
displacement of the bottom of the pendulum `d`. The moment
(M.sub.mw) due to m.sub.w is given by:
M m w = m w g x ##EQU00002## y = d * ( r / l ) ##EQU00002.2## x 2 +
y 2 = r 2 ##EQU00002.3## x 2 + d 2 * ( r / l ) 2 = r 2
##EQU00002.4## x 2 = r 2 * ( 1 - ( d l ) 2 ) ##EQU00002.5## x = r *
( 1 - ( d l ) 2 ) ##EQU00002.6##
Substituting for x above, we have:
M m w = m w g r * . ( 1 - ( d l ) 2 ) ##EQU00003##
[0089] The moment due to m.sub.s is given by:
M.sub.ms=m.sub.s*g*d
[0090] The horizontal force F at S is given by:
F=M/h
[0091] Where
h 2 + d 2 = l 2 ##EQU00004## h = l * ( 1 - ( d l ) 2 )
##EQU00004.2##
[0092] Substituting for h above, we have:
F = M / ( l * ( 1 - ( d l ) 2 ) ##EQU00005##
[0093] Substituting for M, we have
F = ( M mw + M ms ) / ( l * ( 1 - ( d l ) 2 ) F = ( ( m w * g * r *
. 1 - ( d l ) 2 ) + ( m s * g * d ) ) / ( l * ( 1 - ( d l ) 2 )
##EQU00006##
[0094] Assuming that d<<l, we have
F .apprxeq. m w * g * ( r l ) + m s * g * ( d l ) ##EQU00007##
[0095] So, in the final analysis of some of the aforementioned
embodiments, the force due to m.sub.w is approximately independent
of d. In addition, the force due to m.sub.s is proportional to
d.
[0096] To improve the performance of pendulum screen shakers, it
may be desirable to have a force that is independent of the
displacement d. As the force due to the mass on the end of the
pendulum is proportional to the displacement, it may be desirable
to minimize this effect. In one embodiment, it may be noted that a
mass on an arm attached to the screen shaker at the pivot,
perpendicular to the pendulum, tends to cause a force that is
approximately independent of displacement.
[0097] As it is noticed that even a very small force against the
screen may cause a visually undesirable dimple, it may be desirable
to minimize this effect. As the voicecoil assembly and the pendulum
have some mass, there tends to be some force proportional to the
displacement. Thus, in one embodiment that may tend to solve this,
it may be possible to extend the pendulum above the pivot and add a
counterweight so that the center of mass of the pendulum (e.g., not
including the arm and mass M.sub.w) is at the pivot.
[0098] FIG. 9B depicts one such embodiment of a pendulum screen
shaker 902 comprising such a counterweight. As seen, shaker 902
comprises voicecoil 104 (e.g. without any added weight) and
positioned below the pivot (e.g. distal from the pivot). An
adjustment weight 906 is attached at the end of arm 904 at or near
the pivot of the pendulum. Counterweight 908 is shown as attached
above (e.g., proximal from) the pivot of the pendulum. Shaker may
be given mechanical and electrical attachment at 910. It will be
appreciated that many different designs are possible of a pendulum
screen shaker with counterweight and that the scope of the present
application encompasses all such embodiments. In another
embodiment, a counterweight may be added to the shaker on the
distal side of the mount and the actuator is affixed on the
proximal side of the mount. Other design variations are possible
and are encompassed by the scope of the present application.
[0099] FIGS. 10A through 10B and FIGS. 11A through 11C depict
several different views of one particular embodiment of a pendulum
screen shaker comprising a counterweight. FIGS. 12A and 12B depict
one embodiment of a pendulum screen shaker comprising a
counterweight at rest and with relative motion between positions
1202, 1204 and 1206.
Other Embodiments
[0100] FIG. 13 is yet another embodiment of a dual linkage screen
shaker comprising a fixed support member 1302 attached at the
structure at pivots 1308--which are also in mechanical
communication with members 1306a and 1306b. Members 1306a and 1306b
are in mechanical communications with swinging horizontal member
1310 (at other pivots 1308, as shown). As may be seen, an actuator
may be coupled at the end of the swinging horizontal member, which
in turn may bring the actuator into mechanical communication with
the screen.
[0101] This dual-linkage mount and/or structure (as depicted in
FIG. 13) may tend to prevent rotation of actuator 102 as the screen
moves. Although, in some embodiments, a long pendulum (i.e.,
l>>d) may reduce this rotation, this dual-linkage
mount/structure may tend to allow no rotation and would tend to
eliminate any asymmetrical imprint of the actuator in the
screen.
[0102] As mentioned above, the placement structure may comprise,
for example, a dual arm dual-pivot swing that maintains a coupler
of the shaking device parallel to the screen. In one embodiment,
the placement device comprises a dual arm dual-pivot swing that
maintains a coupler of the shaking device parallel to the screen
while moving due to screen movement. The placement device may
comprise, for example, parallelism mechanism configured to maintain
a coupler of the shaker parallel to the screen while moving due to
screen movement. The placement device may comprise a coupler motion
parallel placement mechanism configured to maintain a coupler of
the shaker parallel where it would otherwise not be parallel due to
shaker induced movement.
[0103] FIG. 14 is one embodiment of voice coil mount in the manner
of a diving board and/or cantilevered section. Member 1402 may have
attached/affixed (or in some manner mechanically mated) a diving
board (or cantilevered member) 1410 at 1406. This attachment as
shown is bolted--but, it should be appreciated that the mechanical
mating may be accomplished by any known manner. An optional second
member 1408 may be provided for added stability (and a window
and/or void section 1404 may be cut out from member 1402 to allow
for movement). Voicecoil 1412 may be attached to the diving board
section 1410--and by which the actuator (not shown) may be attached
at portion 1414.
[0104] As shown, voicecoil 1412 may be mounted with a parallel
linkage to prevent rotation of the actuator/voicecoil over the
range of travel and/or vibration. In one embodiment, the placement
structure may comprise, for example, a parallelogram shaped device
maintains a position of the shaker parallel to the screen during
motion of the screen due to air currents or other disturbances and
a parallelogram that maintains a face of the shaker parallel to the
screen despite motion of the face due to shaker vibrations. The
parallelogram shaped device may be mounted, for example on an arm
having a cut-away ("window") that allows the parallelogram shaped
device to vibrate freely. Alternatively a device the functions as a
parallelogram, maintaining the shaker or its transducer/coupler
element parallel to the screen and mounted such that it can vibrate
freely.
[0105] In yet another embodiment, a more cost-effective solution
may be to construct the "diving board" as a single cantilever mount
(e.g., where the optional second member 1408 is not provided). In
this case, the rotation of the actuator/voicecoil may be reduced by
extending the length of the cantilever section.
[0106] A detailed description of one or more embodiments of the
invention, read along with accompanying figures, that illustrate
the principles of the invention has now been given. It is to be
appreciated that the invention is described in connection with such
embodiments, but the invention is not limited to any embodiment.
The scope of the invention is limited only by the claims and the
invention encompasses numerous alternatives, modifications and
equivalents. Numerous specific details have been set forth in this
description in order to provide a thorough understanding of the
invention. These details are provided for the purpose of example
and the invention may be practiced according to the claims without
some or all of these specific details. For the purpose of clarity,
technical material that is known in the technical fields related to
the invention has not been described in detail so that the
invention is not unnecessarily obscured.
* * * * *